Arabidopsis thaliana: A model host plant to study plant-pathogen interaction using Chilean field isolates of Botrytis cinerea

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000200004&lng=es&nrm=isoOne of the fungal pathogens that causes more agriculture damage is Botrytis cinerea. Botrytis is a constant threat to crops because the fungus infects a wide range of host species, both native and cultivated. Furthermore, Botrytis persists on plant debris in and on the soil. Some of the most serious diseases caused by Botrytis include gray mold on vegetables and fruits, such as grapes and strawberries. Botrytis also causes secondary soft rot of fruits and vegetables during storage, transit and at the market. In many plant-pathogen interactions, resistance often is associated with the deposition of callose, accumulation of autofluorescent compounds, the synthesis and accumulation of salicylic acid as well as pathogenesis-related proteins. Arabidopsis thaliana has been used as a plant model to study plant-pathogen interaction. The genome of Arabidopsis has been completely sequenced and this plant serves as a good genetic and molecular model. In this study, we demonstrate that Chilean field isolates infect Arabidopsis thaliana and that Arabidopsis subsequently activates several defense response mechanisms associated with a hypersensitive response. Furthermore, we propose that Arabidopsis may be used as a model host species to analyze the diversity associated with infectivity among populations of Botrytis cinerea field isolates

Genomics in aquaculture to better understand species biology and accelerate genetic progress

From a global perspective aquaculture is an activity related to food production with large potential for growth. Considering a continuously growing population, the efficiency and sustainability of this activity will be crucial to meet the needs of protein for human consumption in the near future. However, for continuous enhancement of the culture of both fish and shellfish there are still challenges to overcome, mostly related to the biology of the cultured species and their interaction with (increasingly changing) environmental factors. Examples of these challenges include early sexual maturation, feed meal replacement, immune response to infectious diseases and parasites, and temperature and salinity tolerance. Moreover, it is estimated that less than 10% of the total aquaculture production in the world is based on populations genetically improved by means of artificial selection. Thus, there is considerable room for implementing breeding schemes aimed at improving productive traits having significant economic impact. By far the most economically relevant trait is growth rate, which can be efficiently improved by conventional genetic selection (i.e. based on breeding values of selection candidates). However, there are other important traits that cannot be measured directly on selection candidates, such as resistance against infectious and parasitic agents and carcass quality traits (e.g. fillet yield and meat color). However, these traits can be more efficiently improved using molecular tools to assist breeding programs by means of marker-assisted selection, using a few markers explaining a high proportion of the trait variation, or genomic selection, using thousands of markers to estimate genomic breeding values. The development and implementation of new technologies applied to molecular biology and genomics, such as next-generation sequencing methods and high-throughput genotyping platforms, are allowing the rapid increase of availability of genomic resources in aquaculture species. These resources will provide powerful tools to the research community and will aid in the determination of the genetic factors involved in several biological aspects of aquaculture species. In this regard, it is important to establish discussion in terms of which strategies will be more efficient to solve the primary challenges that are affecting aquaculture systems around the world. The main objective of this Research Topic is to provide a forum to communicate recent research and implementation strategies in the use of genomics in aquaculture species with emphasis on (1) a better understanding of fish and shellfish biological processes having considerable impact on aquaculture systems; and (2) the efficient incorporation of molecular information into breeding programs to accelerate genetic progress of economically relevant traits

Analysis of the association between spawning time QTL markers and the biannual spawning behavior in rainbow trout (Oncorhynchus mykiss)

The rainbow trout is a salmonid fish that occasionally exhibits broodstocks with biannual spawning behavior, a phenomenon known as a double annual reproductive cycle (DARC). Spawning time quantitative trait loci (SPT-QTLs) affect the time of the year that female rainbow trout spawn and may influence expression of the DARC trait. In this study, microsatellite markers linked and unlinked to SPT-QTLs were genotyped to investigate the underlying genetics of this trait. SPT-QTLs influenced the DARC trait since in two case-control comparisons three linked markers (OmyFGT12TUF, One3ASC and One19ASC) had significant levels of allelic frequency differentiation and marker-character association. Furthermore, alleles of One3ASC and One19ASC had significantly higher frequencies in populations that carried the DARC trait

Cultivo de la trucha caf\ue9 an\ue1droma: una nueva alternativa para la diversificaci\uf3n de la salmonicultura nacional

Con el propósito de aportar información para contribuir al desarrollo del cultivo de la trucha café anádroma (Salmo trutta trutta) en Chile, también llamada seatrout, en este trabajo se revisan los siguientes aspectos: i) características genéticas y origen evolutivo de la trucha café naturalizada existente en el país, ii) rendimiento reproductivo bajo condiciones de cautiverio, and iii) eficiencia del proceso de esmoltificación, tasa de crecimiento y maduración sexual en agua dulce y agua de mar de la trucha café anádroma. Estos últimos parámetros son particularmente relevantes para una apropiada evaluación de su desempeño bajo condiciones de cultivo intensivo. El análisis de estos aspectos indica que las poblaciones naturalizadas de trucha café en Chile presentan un alto grado de variación genética, junto con un probable origen único (línea filogenética Atlántica, norte de Europa); éstas también presentan un rendimiento reproductivo óptimo, que excede aquel observado en otros salmónidos. Además, el proceso de esmoltificación de la trucha café anádroma es equivalente al observado en salmónidos totalmente anádromos, como el salmón del Atlántico y el salmón coho. Asimismo, con excepción de la maduración precoz, que es más alta que en el salmón del Atlántico, sobre todo en los machos, esta variedad también muestra una favorable tasa de crecimiento y sobrevivencia en agua de mar. Todos estos antecedentes indican que el cultivo de la trucha café anádroma es una alternativa interesante, con potencial para ser incorporada en la salmonicultura nacional

Molecular genetic studies of Chilean avifauna: an overview about current progress

The biodiversity of Chilean avifauna has been shaped by geological events, geographical factors and extreme climatic regimens. Molecular genetic studies developed to date have begun to provide valuable information to elucidate the effect of these factors on the evolutionary history of Chilean birds. We conducted a search in two bibliographic databases (PubMed and Scopus) over the period between 1998 and 2018 to identify the number and class of articles published in this research field. The quantification of specific research categories was also performed to assess progress in different molecular genetic issues of Chilean birds. Representative studies of the more active research areas: population structure, phylogeography, systematics and taxonomy and genetic diversity, were briefly commented on. Studies on genetic divergence analysis of cryptic species and the underlying genetics at molecular level of adaptive phenotypes in populations, were very scarce. Several types of mitochondrial and nuclear markers have been used, with COI plus D-loop and microsatellite loci, respectively, being the most widely-used markers. However, high-throughput analyses based on complete mitochondrial genomes have also been published. More than one hundred species have been analyzed; the most studied groups being penguins, followed by New World swallows. Although, to date, molecular genetic studies of Chilean birds still require further analysis, the studies available on some species or groups have provided important data to improve our understanding of the origin and evolution of this avifauna